Routing header based routing in internet protocol (IP)-cellular networks

ABSTRACT

Internet protocol version 6 (IPv6) is substantially utilized throughout the entire cellular network and employs routing headers of the packets to ensure that the packets are routed via the gateway router (GR) to the end destination which is accomplished by a user equipment (UE) specifying the IP address of the gateway router as the IP address of an intermediate router in the routing header. Packets may also be routed to UEs from the GR through an intermediate router.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional application No. 60/393,358 filed on Jul. 1, 2002, and application Ser. No. 10/328,662 filed on Dec. 23, 2002 which are incorporated by reference as if fully set forth.

BACKGROUND

This invention relates to cellular networks. More particularly, the invention relates to a technique employing routing headers in internet protocol (IP) packets to route packets to an end destination through intermediate routers employing routing headers.

FIG. 1 shows a typical cellular network such as a Global System for Mobile Communications/Generalized Packet Switched Service (GSM/GPRS) network. In IP-applications there is a single point of attachment to the external IP-networks such as the Public Internet, the single point of attachment being a gateway general packet radio service support node (GGSN) also referred to in FIG. 1 as the gateway router GR. The Gateway Router is connected to the Public Internet and also to X.25 Networks via Firewalls F2 and F1, respectively. On the radio network side, the Gateway Router is coupled to the intra-public land mobile network (Intra-PLMN) internet protocol (IP) backbone for sending two-way data from multiple user equipments (UEs). The IP-layer in the user equipment (UE) terminates at the GGSN which, in turn, means that there is a single “IP-level-hop” from the UE to the GGSN. FIG. 2 shows the protocol stacks used for exchanging IP data between the user equipment, also referred to as the mobile station (MS), base station sub-system (BS), the serving GPRS support node (SGSN) and the gateway GPRS support node (GGSN).

Typically, the UMTS network is made up of switching elements which transfer the IP-packets through the employment of Layer-2 switching techniques. Some UMTS networks utilize IP-based routing elements. However, the IP-technology is used purely for transport purposes only and is not visible to the UE, meaning that the IP-layer of the UE is still terminated at the GGSN.

It is a clear possibility that future cellular networks will be entirely IP-based. In other words, the cellular network will be an interconnected network of IP-routers with the result that the IP-layer of the UE may be terminated by a nearby router. However, since the network is still assumed to have a single point of attachment to the external IP-networks, IP packets from the nearest router must be routed to the gateway router GR (for example, the GGSN shown in FIG. 1). In the prior art, this is achieved by establishing IP-tunnels which involve IP-in-IP encapsulation. This approach has the disadvantages of requiring the need to set up tunnels and the extra overhead due to encapsulation.

Another scenario is a network of a number of LAN Access Routers (ARs), wherein each Access Router is connected to a number of Access Points, as shown in FIG. 3. A single gateway router serves these ARs and provides connectivity to the external IP-networks. Such a network may also be referred to as an Autonomous System or an IP-domain. Other scenarios include universal mobile telecommunications system (UMTS) networks, code division multiple access CDMA2000 networks etc.

SUMMARY

The present invention utilizes internet protocol version 6 (IPv6) throughout the entire cellular network and employs routing headers of the IPv6 packets to ensure that the packets are routed via the gateway router to the end destination which is accomplished by specifying the IP address of the gateway router as the IP address of an intermediate router in the routing header.

BRIEF DESCRIPTION OF THE DRAWING(S)

The present invention will be understood from a consideration of the figures in which like elements are designated by like numerals and, wherein:

FIG. 1 shows a typical global system for mobile communications/general packet radio service (GSM/GPRS) cellular network.

FIG. 2 shows the layers making up the mobile station, base station, SGSN and GGSN of FIG. 1.

FIG. 3 shows a network employing WLAN Access Routers connected to a number of Access Points.

FIG. 4 shows a network similar to the network of FIG. 3 and further describing the manner in which routers are used as intermediate nodes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The present invention eliminates the disadvantages of the prior art through the utilization of internet protocol version 6 (IPv6) throughout the entire Cellular Network and using Routing Headers of IPv6 packets to ensure that the packets are routed via the gateway router to the end destination. This is accomplished through the present invention by specifying the IP-address of the gateway router as an IP-address of an intermediate router in the routing header.

As shown in FIG. 3, user IP packets are sent from the UE (see also FIG. 1) to the nearest router NR shown, by way of the radio tower T (see FIGS. 1 and 3) and then to the gateway router GR. The IPv6 header of the User IP packets contain the IP addresses of the Gateway Router GR in the Routing Header. At a minimum, the Gateway Router is a simple IP Router that can route IP packets based on their destination IP address. However, the Gateway Router may have additional features, such as Source Address based Routing, Network Address Translation, QoS based Routing (such as DiffServ, MPLS etc), Secure Firewalls, etc. In addition, the gateway router has the capability of sending messages to the UE as to the addresses of those routers which may be included in a routing header in order to select a router or routers having smaller or no traffic loads.

Another aspect of the invention is the provision of additional routers which serve as nodes. The selection of intermediate routers is based on criteria such as congestion state and/or capacity and/or monitoring needs. For example, noting FIG. 4, the user IP packets are sent from the UE through radio tower T to the nearest router NR, typically referred to as an access router, by way of the radio tower T and then to an intermediate node router such as IN1 and finally to the gateway router GR, serving as the gateway to the internet. The reason for routing the IP packets via IN1 may be that IN1 is not congested with excessive traffic, compared to other routers that could have been used to send IP packets from NR to GR. Alternately, the reason for routing the IP packets via IN1 may be that traffic monitoring equipment is connected to IN1, and a legal requirement that all IP packets emanating from one or more UEs are to be monitored. The IPv6 header of the User IP packets contain the IP addresses of the intermediate router IN1 and the Gateway Router GR in the Routing Header, eliminating the need for tunneling and encapsulation. There are several ways in which the IPv6 routing headers are populated with the appropriate IP addresses of the Gateway Router as well as additional Intermediate Routers.

As one example, the UE constructs the IPv6 packets with this routing header information. This method requires that the UE is made aware of the necessary information regarding the IPv6 addresses of the GR and the Intermediate Nodes. For example, the Network may inform the UE prior to data transmission.

Another technique is to allow the NR to perform this task. In this scenario, the UE need not be aware of the IP routing within the cellular network at all. In fact, the UE may even be an IPv4 device. The Nearest Access Router will be equipped to perform address translation (from IPv4 to IPv6) if necessary and to add the appropriate IPv6 Routing Header. The advantage of this technique is that the NR, being part of the fixed network of the cellular system, can be made aware of the network status (in terms of congestion, failures etc), as well as the need for processing by special intermediate nodes for purposes such as legal interception.

As another alternative embodiment, the GR may add and/or modify routing headers of received packets and convey the packets to a UE through an access router, access router being a standard term typically designated as the first router communicating with a UE through a radio tower. 

1. A method employed in a cellular network having a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR) and a gateway router, said method ensuring that internet protocol (IP) packets from a user equipment (UE) are routed by the gateway router (GR) to an end destination, comprising: said UE: selecting an AR; providing IP addresses of the GR and a destination in each routing header a group of packets; and transmitting packets to said radio tower employing internet protocol version 6 (IPv6); said AR: sending the IP packets to the GR responsive to information in the routing headers; and said GR: sending the IPv6 packets received from the AR to the destination through the internet.
 2. The method of claim 1, said AR: intercepting said IPv6 packets and inserting an address of at least another one of said routers which serves as an intermediate node.
 3. The method of claim 2, the AR: selecting an intermediate node to avoid network congestion.
 4. The method of claim 2, the AR: selecting the intermediate node to enable lawful interception of the packets.
 5. The method of claim 2, the AR: selecting an intermediate node configured to monitor traffic.
 6. A method employed in a cellular network having a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR) and a gateway router, said method ensuring that internet protocol (IP) packets from a user equipment (UE) are routed by the gateway router (GR) to an end destination, comprising: said UE: selecting an AR; providing an IP address of a destination in each routing header of a group of packets; and transmitting packets to said radio tower; said AR: providing packet headers of the packets from said UE with at least a routing address of said GR; and sending said IP packets to the GR responsive to information in the routing headers; and said GR: sending the IPv6 packets received from the AR to the destination through the internet.
 7. The method of claim 6, said AR: converting packets received from the UE into internet protocol version 6 (IPv6) format; and inserting the GR address in IPv6 headers of the IPv6 formatted packets.
 8. The method of claim 6, said UE: sending the packets to the radio tower employing internet protocol version 4 (IPv4) format; and said AR: converting packets received from the UE into internet protocol version 6 (IPv6) format; and inserting the GR address in headers of the IPv6 formatted packets.
 9. The method of claim 6, wherein the insertion step performed by the AR further comprises: inserting an address of at least another one of said routers which serves as an intermediate node.
 10. The method of claim 9, the AR: selecting the intermediate node to avoid network congestion.
 11. The method of claim 9, the AR: selecting the intermediate node to enable lawful interception.
 12. The method of claim 9, the AR: selecting an intermediate node configured to monitor traffic.
 13. A method employed in a cellular network having a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR) and a gateway router, said method ensuring that internet protocol (IP) packets from a user equipment (UE) are routed by the gateway router (GR) to an end destination, comprising: said AR: sending to the UE packet header addresses for packets to be sent by the UE comprising at least a routing address of said GR; said UE: providing an IP address of a destination and the GR address in each routing header of a group of packets; and transmitting packets to said radio tower; and said AR: sending said IP packets to the GR responsive to information in the routing headers; and said GR: sending the IPv6 packets received from the AR to the destination through the internet.
 14. The method of claim 13, said UE: sending the packets to the radio tower employing internet protocol version 6 (IPv6) format.
 15. The method of claim 13, wherein the insertion step performed by the AR further comprises: inserting an address of at least another one of said routers which serves as an intermediate node.
 16. The method of claim 15, the AR: selecting the intermediate node to avoid network congestion.
 17. The method of claim 15, the AR: selecting the intermediate node to enable lawful interception.
 18. The method of claim 15, the AR: selecting an intermediate node configured to monitor traffic.
 19. A method employed in a cellular network having a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR) and a gateway router, said method ensuring that internet protocol (IP) packets from a user equipment (UE) are routed by the gateway router (GR) to an end destination, comprising: said UE: obtaining internet protocol version 6 (IPv6) formatted addresses of at least the GR from the network; selecting an AR; providing IP addresses of the GR and a destination in a routing header a group of packets; and transmitting the packets to said radio tower; said AR: sending said IP packets to the GR responsive to information in the routing headers; and said GR: sending the IPv6 packets received from the AR to the destination through the internet.
 20. The method of claim 19, wherein the insertion step performed by the AR further comprises: inserting an address of at least another one of said routers which serves as an intermediate node.
 21. The method of claim 19, the AR: selecting the intermediate node to avoid network congestion.
 22. The method of claim 19, the AR: selecting the intermediate node to enable lawful interception.
 23. The method of claim 19, the AR: selecting an intermediate node configured to monitor traffic.
 24. The method of claim 19, said AR: selecting addresses of a least two of the plurality of routers based on a determination of traffic loads of said plurality of routers.
 25. Cellular network apparatus for ensuring that internet protocol (IP) packets from a user equipment (UE) are properly routed to an end destination, comprising: a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR); a gateway router; said UE comprising: means for selecting an AR; means for providing IP addresses of the GR and a destination in a routing header a group of packets; and means for transmitting packets to said radio tower employing internet protocol version 6 (IPv6); said AR comprising: means for sending the IP packets to the GR responsive to information in the routing headers; and said GR comprising: means for sending the IPv6 packets received from the AR to the destination through the internet.
 26. The apparatus of claim 25, said AR comprising: means for intercepting said IPv6 packets and inserting an address of at least another one of said routers which serves as an intermediate node.
 27. The apparatus of claim 26, the AR comprising: means for selecting an intermediate node to avoid network congestion.
 28. The apparatus of claim 26, the AR comprising: means for selecting the intermediate node to enable lawful interception of the packets.
 29. The apparatus of claim 26, the AR comprising: means for selecting an intermediate node configured to monitor traffic.
 30. Apparatus employed in a cellular network for ensuring that internet protocol (IP) packets from a user equipment (UE) are properly routed, comprising: a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR); a gateway router (GR); said UE comprising: means for selecting an AR; means for providing an IP address of a destination in each routing header of a group of packets; and means for transmitting packets to said radio tower; said AR comprising: means for providing packet headers of the packets from said UE with at least a routing address of said GR; and means for sending said IP packets to the GR responsive to information in the routing headers; and said GR comprising: means for sending the IPv6 packets received from the AR to the destination through the internet.
 31. The apparatus of claim 30, said AR comprising: means for converting packets received from the UE into internet protocol version 6 (IPv6) format; and means for inserting the GR address in IPv6 headers of the IPv6 formatted packets.
 32. The apparatus of claim 30, said UE comprising: means for sending the packets to the radio tower employing internet protocol version 4 (IPv4) format; and said AR comprising: means for converting packets received from the UE into internet protocol version 6 (IPv6) format; and means for inserting the GR address in headers of the IPv6 formatted packets.
 33. The apparatus of claim 30, wherein the means for insertion performed by the AR further comprises: means for inserting an address of at least another one of said routers which serves as an intermediate node.
 34. The apparatus of claim 33, the AR comprising: means for selecting the intermediate node to avoid network congestion.
 35. The apparatus of claim 33, the AR comprising: means for selecting the intermediate node to enable lawful interception.
 36. The apparatus of claim 33, the AR comprising: means for selecting an intermediate node configured to monitor traffic.
 37. Apparatus employed in a cellular network for ensuring that internet protocol (IP) packets from a user equipment (UE) are properly routed, comprising: a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR); a gateway router (GR); said AR comprising: means for sending to the UE packet header addresses for packets to be sent by the UE comprising at least a routing address of said GR; said UE comprising: means for providing an IP address of a destination and the GR address in each routing header of a group of packets; and means for transmitting packets to said radio tower; and said AR comprising: means for sending said IP packets to the GR responsive to information in the routing headers; and said GR comprising: means for sending the IPv6 packets received from the AR to the destination through the internet.
 38. The apparatus of claim 37, said UE comprising: means for sending the packets to the radio tower employing internet protocol version 6 (IPv6) format.
 39. The apparatus of claim 38, wherein the AR further comprises: means for inserting an address of at least another one of said routers which serves as an intermediate node.
 40. The apparatus of claim 39, the AR comprising: means for selecting the intermediate node to avoid network congestion.
 41. The apparatus of claim 39, the AR comprising: means for selecting the intermediate node to enable lawful interception.
 42. The apparatus of claim 39, the AR comprising: means for selecting an intermediate node configured to monitor traffic.
 43. Apparatus employed in a cellular network for ensuring that internet protocol (IP) packets from a user equipment (UE) are properly routed, comprising: a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR); a gateway router (GR); said UE comprising: means for obtaining internet protocol version 6 (IPv6) formatted addresses of at least the GR from the network; means for selecting an AR; means for providing IP addresses of the GR and a destination in a routing header a group of packets; and means for transmitting the packets to said radio tower; said AR comprising: means for sending said IP packets to the GR responsive to information in the routing headers; and said GR comprising: means for sending the IPv6 packets received from the AR to the destination through the internet.
 44. The apparatus of claim 43, wherein the AR further comprises: means for inserting an address of at least another one of said routers which serves as an intermediate node.
 45. The apparatus of claim 44, the AR comprising: means for selecting the intermediate node to avoid network congestion.
 46. The apparatus of claim 44, the AR comprising: means for selecting the intermediate node to enable lawful interception.
 47. The apparatus of claim 44, the AR comprising: means for selecting an intermediate node configured to monitor traffic.
 48. The apparatus of claim 44, said AR comprising: means for selecting addresses of a least two of the plurality of routers based on a determination of traffic loads of said plurality of routers.
 49. Apparatus employed in a system for ensuring that internet protocol (IP) packets from a user equipment (UE) are properly routed, said system comprising: at least one cellular network, a WLAN network and a radio network; the cellular network comprising: at least one UE; a plurality of routers, at least one of said routers being connected to an access point having a radio tower and designated as an access router (AR), and a gateway router (GR); said UE comprising: means for selecting an AR; means for providing IP addresses of the GR and a destination in a routing header a group of packets; and means for transmitting packets to said radio tower employing internet protocol version 6 (IPv6); and said AR comprising: means for sending user IP packets received from said UE to the GR responsive to information in the routing header; and said GR comprising: means for sending the IPv6 packets received from the AR to the destination through the internet. 